If your vehicle is not saleable, then there are plenty of scrap car processors who will dispose of your car for no fee. Make sure you choose an Authorised Treatment Facility (ATF), and that you obtain a Certificate of Destruction (COD) from them to enable you to cancel your road tax and vehicle registration from DVLC.

Antifreeze is usually made from a combination of ethylene glycol (and toxin) and methanol (ditto). It should never be disposed of into the water supply.

Antifreeze from your car can be re-used directly: give it to somebody who can use it, or ask your local garage if they can use it. Alternatively, most coucils have a disposal facility at their household waste recycling centre.

Local councils have facilities for oil disposal.